Kassam had spent the last year and a half volunteering as an English teacher at a school funded by the Aga Khan Foundation.

Thomas spent weeks at a time living in Afghanistan's impoverished communities and opened her Canadian home to youth seeking opportunities outside the war-torn country.

The women were among the nine people killed at the Serena Hotel in Kabul on Thursday.

Karim Thomas, Roshan's only son, said his mother was in Afghanistan helping to screen and select Afghan youth for an international scholarship program.

It was just one of her many efforts to level the playing field and bring new opportunities to the country she had visited regularly for the past 11 years, he said.

Afghan security personnel near the Serena Hotel in Kabul. Taliban gunmen attacked patrons inside the luxury hotel on Thursday. Four assailants were killed in a shootout with Afghan security forces. (Ahmad Masood/Reuters)

"She felt it was important to educate both girls and boys because without that balance of educated children becoming educated adults, you wouldn't have a society that could progress and develop equally," he said in a telephone interview from Vancouver.

His mother's work with Afghan youth began in the mid-1990s when she began volunteering alongside her husband, an ophthalmologist, to provide eye treatment to refugees fleeing Taliban rule.

When those refugees returned home, Thomas followed them and began her crusade for better education.

She opened a school for Afghan children and recently became more involved in offering opportunities for them to study abroad, Karim Thomas said, adding that six Afghan youth are currently living in his parents' Metro Vancouver home.

Karim Thomas said the knowledge that his mother made a genuine difference in the world has helped him, his father and his two sisters cope with the shock of her sudden death, which came months before she was expected to welcome her first grandchild into the world.

"It's been quite overwhelming, the amount of support, the phone calls, the emails that have come from all over the world with stories about how my mother touched their lives," he said. "That's been an incredible source of comfort and strength for us."

Longtime friend Senator Mobina Jaffer was also struggling to come to terms with the death of Thomas.

"She was one of the most unselfish people I know," Jaffer said in a telephone interview from Vancouver. "I had just seen her a few weeks ago; she was doing such good work."

Thomas is survived by her husband and three adult children.

Kassam was volunteering, teaching English

Kassam, 57, was trained as a nurse, and had been living in Alberta for the past 45 years, according to her brother, Karim-Aly Kassam, a Cornell University professor from Ithaca, N.Y.

She was born in Zanzibar, raised in Calgary and got her teaching degree in Edmonton. She was in Afghanistan volunteering as an English teacher, he said.

According to her brother, Kassam was always willing to help others.

"I'm trying to say that this is a very Canadian thing to do. It's what Canadians do. Think about how many people in your neighbourhood volunteer — whether they are dentists, engineers — right? Everybody volunteers," he told Calgary radio station CHQR.

Her brother said he is working with Foreign Affairs to retrieve his sister's body, but has many questions such as whether there were any witnesses. Did she suffer, he wonders? Was there anyone there to hold her hand?

Still, he only has one driving desire at this point: "We just want to bring her home and bury her," he told CBC News.

Lauryn Oates, the projects director for the Calgary-based NGO, Canadian Women for Women in Afghanistan, said the attack is a harsh reminder for everyone in the international aid community.

Oates, who knew both victims, said such tragedies never get easier to accept no matter how often they happen.

"It's something we're braced for all the time and we were well aware that things were dicey," she said. ". . . You just think of their families and what they're going through right now and it's heartbreaking."

The attack that killed Thomas and Kassam came as a shock to a country long accustomed to coping with militant violence.

The Serena Hotel has long been considered one of the safest accommodations in the country. Yet on Thursday night, four teenage gunmen worked their way past security, entered the hotel restaurant and opened fire on diners.

Other victims included a foreign journalist, his wife and their two children.

Police killed all four attackers after a three-hour standoff, with gunshots resounding through the cordoned off streets outside.

Hotel restaurant packed

At the time of the attack, the hotel restaurant was packed with Afghans celebrating the eve of Nowruz, the Persian New Year, as well as foreigners who frequent the hotel.

A view of the Serena Hotel in Kabul a day after it was attacked by Taliban gunmen. Nine people were killed, including two Canadians. (Mohammad Ismail/Reuters)

Foreign Affairs Minister John Baird condemned the brazen attack, but said it would not deter Canadians from fighting terrorism in the country.

He described the two Canadian victims as development workers who were not officially employed by the federal government.

"Many of these people dedicated their lives to helping everyday Afghans build a better country for themselves, including education, and enhancing the role of women and girls in Afghan society. For this selfless work to be met with violence, especially on the occasion of Nowruz, just further proves the depravity of the Taliban and those who support them."

Jaffer agreed.

"For something like this to happen on what was supposed to be a day of celebration, it's just horrible," she said.

The shooting rampage was the latest in a series of high-profile attacks as the Taliban and allied militants step up a campaign of violence in the weeks before the April 5 national elections.